Spark-plug.



P. BARTL.

SPARK PLUG. APPLICATION FILED AUG. 12, 1907.

Patented Apr. 20, 1909.

2 R 9 d W H. .I. i x b w a s 1 v d produce a spark plug of very sim le con- FRANZ BARTL, OF FAR RQGKAWAY, NEW YORK.

srmx-rnue.

ipecification of Letters Patent.

Patented April 20, 1909.

Application fled August 12, 1907. Serial N0. 888,101.

" To. all whom it may concern 'Be it known that I, FRANZ BARTL, a subject of the Em eror of Austria-Hungary,

and a resident 0 Far Rockaway, county of Queens, and State of New York, have invented certain new and useful Im rovements in Spark-Plugs, of which the ollowin is a specification.

his invention has reference to improvements in spark-plu s and pertains particularly to that type w 'ch' is used in explosive en ines for automobiles and the-like t is the special object of my invention to struction composed of but few e ements,

whose parts are absolutely indestructible and provided with an insulation which. forms part thereof and is integral therewith. The insulation used in this new spark-plug resists heat and excessive heat does not crack or break it, but makes same malleable. The two princi al parts of the device are both insulated; t erefore the spark-plug remains operative if one part should be damaged by carelessness or otherwise.

The invention is illustrated in the accompan g drawing,'in which: Figure 1 represents in longitudinal section a spark-plug which embo ies in desirable form the present improvements, and Fig. 2 shows same in cross section on line 22 of 'Fi 1. 1 vimilar characters of reference denote like I which is preferab parts in all the. figures.

In the drawing (1 represents the casing y made of metal and hexagonal in shape, as shown in Fig. 2,-so that a wrench may be applied. The right hand end portion of the casing, as shown 1n Fig. 1, is first somewhat reduced in diameter, as shown at a, and then it is again reduced in diameter and a screw thread a is formed on this last mentioned ortion. In this threaded portion of the s ell a silver wire 8 is in- 45 the plug. The interior surface of the orsorted which is curved toward the center of tion a? of the shell is conically shape as shown in Figs. 1 and 3. The entire interior surface of the shell is insulated by enamel b which is produced thereon in the well known .manner. Thus the insulation on the interior surface of the shell forms part thereof and is integral therewith.

At the left hand end, the shell is open at full width. A plug 0 made of insulating heat is developed by ex losive material such as stone, porcelain, and the like fits into this 0 ening. This plu is provided with a 'shou den: and a was or w is" applied between this shoulder and the adjoining open end of the shell. Anannular incision a and a narrower channel 0 are produced in this plug.

A pin (2 is centrally located within the s arkplug. It has on one end a screw t read d and near the right hand end portion a head (1 of enamel d in ike manner as the interior shell or casing a. The insulation d of the pin extends from the inner end of the screw thread d throughout the entire length of the pin and covers at the right hand end 'a straight silver wire 8 Whose end is in close This in is insulated by a coating roximity to the end of the silver wire s. i

he pin (1 is inserted into the s ark-plu from the right hand end of same an the heai d rests against the conical interior surface of the portion a of the casing. The screw (1 extends beyond the end'of the inserted plug 0 and a nut e fits on said screw.

For tightening the device shown in Fig. 1, the nut c on the screw d is simply turned until it presses against the insulatm stoneor porce ain plu 1; whereby the hea d of the in is presse against the inner conical surace of the ortion o of the shell.

The spar lug operates in the usual manner; the spar passing between the ends of the silver wires 8 and 8. During use, when as, the enamel does not crack, brea or pee off, because the enamel soft'ens slight y and becomes malleable, making thus a more perfect joint between the head d and the inner conical surface of the portion a. so,-that no oil can flow into the interior of the insulating shell. By virtue of the smooth surface of the shell and the pin the spark-plug is easily and quickly cleaned.

It is selfevident that the spark-plu above described is more durable than those eretofore used by virtue of its compactness in construction and insulating material employed therein. In case the shell and the pin moved, the plug is still operative and reliable. Even when both parts, the insulated shell and the insulated pin should be dama edby h accident, so that some metal should e exposed on both parts, the. plu will be operative and reliable.

portion having an mner coatin g of refractory tracted portion of the shell at one end forming mslde nearthe other end portion a narrox' conical surface and ro- No short circuit will be caused so long as the two damaged spots do l not occur too close to ether.

Having thus descrlbed my invention, I claim as new and desire to secure by Letters I curved s arking wire secured in one end portion of t 1e shell, an inner metallic electrode for explo- I centrall located within the shell with a head two parts adapte to lodge on the inner conical surface ofametallic shell with contracted 1 of said shell and provided with an outer coating of enamel, a sparking .wire partly g covercd'by enamel, in the end portion of the on and adapted to become malleable by exi inner electrode, and means provided in the cessive heat, and an inner metallic electrode 1 o posite open end of the shell for securing with a head adapted to lodge in the cont e inner electrode tightly within same.

and having a 5 Signed at N ew York, N. Y. this 9th day of coating of refractory insulating material on August, 1907. the outside, two sparking wires one in each part whose-free ends are arranged closely together, and means for securing the inner} electrode ti htly within the shell. a l 2. An in estructible spark plug for explo l Patent:

1. An indestructible spark plug sive en es comprising essentially consisting Insulating material lastingly produced there- FRANZ BARTL.

Witnesses: v

LUDWIG K. Bonn, JOHN T. CAnMonY.

sive engines comprising a metallic shell open vided with an inner coating of ename a 

